package com.kymatrix.kycarbon.xsmd.common.util;

import java.security.MessageDigest;
import lombok.extern.slf4j.Slf4j;

/**
 * @Description: 加密工具
 */
@Slf4j
public class Md5Util {

    private Md5Util() {

    }

    private static final String[] HEXDIGITS = {
        "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

    /**
     * 字符数组转String
     */
    public static String byteArrayToHexString(byte[] b) {
        StringBuilder resultSb = new StringBuilder();
        for (int i = 0; i < b.length; i++) {
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    /**
     * 字符转String
     */
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return HEXDIGITS[d1] + HEXDIGITS[d2];
    }

    /**
     * MD5编码String
     */
    public static String md5Encode(String origin, String charsetName) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetName == null || "".equals(charsetName)) {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetName)));
            }
        } catch (Exception exception) {
            log.error("异常:", exception);
        }
        return resultString;
    }

}
